J/AJ/109/359 H235 in NGC 752 (Milone+ 1995)
Observations and Analysis of the Contact Binary H235 in the Open Cluster NGC 752
Milone E.F., Stagg C.R., Sugars B.A., McVean J.R., Schiller S.J.,
Kallrath D. H. Bradstreet J.
<Astron. J. 109, 359 (1995)>
=1995AJ....109..359M 1995AJ....109..359M
ADC_Keywords: Clusters, open; Stars, variable; Photometry
Abstract:
The short-period variable star Heinemann 235 in the open cluster NGC
752 has been identified as a contact binary with a variable period of
about 0.4118 d. BVRI light curves and radial velocity curves have been
obtained and analyzed with enhanced versions of the Wilson-Devinney
light curve program. We find that the system is best modeled as an
A-type W UMa system, with a contact parameter of 0.21 ± 0.11. The
masses of the components are found to be 1.18 ± 0.17 and 0.24 ±
0.04 Msun, with bolometric magnitudes of 3.60 ± 0.10 and 5.21 ±
0.13, for the hotter (6500 K, assumed) and cooler (6421 K) components,
respectively, with Delta T = 79 ± 25 K. The distance to the binary
is established at 381 ± 17 pc. H235 becomes one of a relatively
small number of open-cluster contact systems with detailed light curve
analysis for which an age may be estimated. If it is coeval with the
cluster, and with the detached eclipsing and double-lined
spectroscopic binary H219 (DS And), H235 is ∼1.8 Gyr old, and may
provide a fiducial point for the evolution of contact systems. There
is, however, evidence for dynamical evolution of the cluster and the
likelihood of weak interactions over the age of the binary precludes
the determination of its initial state with certainty.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3 80 867 Photoelectric light curve data
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Byte-by-byte Description of file: table3
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Bytes Format Units Label Explanations
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1- 12 F12.4 d HJD Heliocentric Julian Date
15- 20 F6.4 --- Ph1 *[0/1[ Phase of minima from ephemeris 1
23- 28 F6.4 --- Ph3 *[0/1[ Phase of minima from ephemeris 3
31- 35 F5.3 mag dVmag Differential V magnitude
38- 42 F5.3 mag dBmag Differential B magnitude
45- 49 F5.3 mag dRmag Differential R magnitude
52- 56 F5.3 mag dImag Differential I magnitude
59- 64 F6.3 mag d(B-V) Differential (B-V) color
67- 72 F6.3 mag d(V-R) Differential (V-R) color
75- 80 F6.3 mag d(V-I) ?Differential (V-I) color
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Note on Ph1:
Phase of minima calculated using ephemeris (1) from printed paper:
E0 = 2 447 815.338(3), P = 0.411 83(12)d
Note on Ph3:
Phase of minima calculated using ephemeris (3) from printed paper:
E0 = 2 446 785.8660(23), P = 0.411 775 0(10)d
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Origin: AAS CD-ROM series, Volume 4, 1995 Lee Brotzman [ADS] 29-Apr-1995
(HJD completed at CDS)
(End) [CDS] 10-Jul-1995